My completely uneducated guess is that its simply the exact same 9x internal boards, but a new tx case, new switches and pots, with the backlight and usbasp programmer pre installed. I could be wrong, but Im skeptical of HK having advanced SMT equipment necessary to produce the boards themselves. However I'm sure they could easily source existing boards, and install backlights and programmers into a new case by hand.

3) Be great to have a Tx module that is compatible with several Rx formats, where you can select Tx type in model programming. (Not that technically difficult [I am a Tech], the power amp stage of the Tx module is common, as is the control input from the sticks, it is only the encoding that needs to be adapted to any particular Rx type format (Spectrum, 9X, etc...)). How sweet would that be, no one has done it YET !. One Tx'r that could be used with all your models, even if they are fitted with different Rx types (spectrum PNF micros, HK 9X, etc...).

cleansurf, could this kind of switching be done with something like er9x?

re: Multiple Rx'r compatibility (9x, Spectrum, JR, etc..)
Unlikely ER9X could achieve this, unless encoding is done on the main board. The original 9X had an interchangeable Tx'r module, which means the serial control input data was encoded in the first stage of the Tx'r module before being amplified and Tx'd out the antenna. Fair guess the encoding is still done in the 9X v2 Tx'r module. So software would not be able to achieve changing Tx'r encoding with the 9X hardware set up. Major bummer.

It would be possible to use firmware to allow different models to select different Rx'r compatibility if the 9XR hardware was designed for it, which would probably not be that difficult, if they are starting from scratch on the main board.

The 9XR would need to encode the serial control data on the main board using software, not a preset hardware encoder. This would enable the data to be encoded to be compatible with whatever Rx'r make you wanted. Not just one type, but a different Rx compatability for each model memory if you wanted. Means you could also add new encoding (Rx compatibility) with firmware upgrades. The 9XR main board would have to be specifically designed to achieve this, maybe V2, V1 to far along now I would guess.

It would be possible to use firmware to allow different models to select different Rx'r compatibility if the 9XR hardware was designed for it, which would probably not be that difficult, if they are starting from scratch on the main board.

The 9XR would need to encode the serial control data on the main board using software, not a preset hardware encoder. This would enable the data to be encoded to be compatible with whatever Rx'r make you wanted

this is not even remotely possible. there is a standard interface that is the same for main boards. its called ppm. there is no "data encoding". its the rf module which determines compatibilty today. specifically the transceiver chip. a7105 for flysky, cc2500 for frsky, rfm22b for olrs, etc.. but they all take ppm in.